Cartridge for phonograph pickup



Aug. 7, 1962 Filed Aug. 28, 1959 C. F. JENSEN CARTRIDGE FOR FHONOGRAPH PICKUP 2 Sheets-Sheet l 1962 c. F. JENSEN 3,048,667

CARTRIDGE FOR PHONOGRAPH PICKUP 2 Sheets-Sheet 2 Filed Aug. 28, 1959 jr-ce/erzd'r warm/ 7 er:

exam (19 United States Patent ()fiice 3,048,667 Patented Aug. 7, 1962 3,048,667 CARTRIDGE FOR PHONUGRAPH PICKUP Clarence F. Jensen, Lombard, 11., assignor to Jensen Industries, Inca, Forest Park, 111., a corporation of Illinois Filed Aug. 28, 11959, Ser. No. 836,811 6 Claims. (Cl. 179-10041) This invention relates generally to a replaceable phonograph pickup cartridge having an elongated hollow housing with exterior contact members for engagement with conducting parts of a phonograph pickup arm and supporting along its longitudinal axis an elongated transducer and stylus supporting member which projects at one end from the housing and carries one or more record engaging styli exteriorly of the housing. When the styli become worn, the cartridge is removed from the pickup arm for examination and replacement, if necessary, by grasping the exterior of the end of the housing adjacent the styli and pulling the housing along its axis.

One object of the invention is to construct the housing and stylus supporting member in a novel manner facilitating removal of the cartridge while avoiding disassembly of the member from the housing.

A more detailed object is to prevent the removal of the stylus support from the housing by the provision of abutments arranged on the housing and the support in a novel manner to be brought into opposing relation automatically as an incident to assembly of these parts.

The invention also resides in the novel construction and arrangement of the housing and the contact members facilitating assembly of these parts while insuring that they remain assembled in use.

Other objects and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawings in which:

FIGURE 1 is a side elevational view of a phonograph cartridge embodying the novel features of the present invention;

FIG. 2 is a plan view of the cartridge;

FIG. 3 is a rear end view looking along the line 3-3 of FIG. 1;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 1;

FIG. 5 is an exploded perspective view of the transducer element and mounting parts;

FIG. 6 is a view similar to FIG. 1 with one-half of the housing removed;

FIG. 7 is a view similar to FIG. 2 with one-half of the housing removed;

FIG. 8 is a perspective view of one contact plate;

FIG. 9 is a fragmentary enlarged view similar to FIG. 2 without the resilient disk between the contact plates;

FIG. 10 is a sectional view taken along the line 1010 of FIG. 9;

FIG. 11 is a view similar to FIG. 8 with the disk between the plates;

FIG. 12 is a sectional view taken along the line 12-12 of FIG. 11.

The invention is shown in the drawings for purposes of illustration embodied in a cartridge 15 adapted to fit into the tone arm 16 of a phonograph pickup and having one or more styli 17 disposed exteriorly for engagement with a phonograph record 18 moving beneath the arm. Generally, the cartridge comprises an elongated hollow housing 19 and a transducer and stylus supporting member 20 extending along the longitudinal axis of the housing and projecting at one end beyond the housing and through an opening 21 therein to dispose the styli exteriorly.

In this instance, the housing 19 is formed of a suitable thermosetting resin and is divided into two parts along a diametrical plane extending through the axis, these parts abutting each other circumferentially in the plane. To provide clearance for the styli, one end portion of each half adjacent the opening 21 and the styli tapers outwardly to form an extension 22 spaced transversely of the housing axis from the extension of the other half. Herein, the sides of these extensions are flat as indicated at 23. Rearwardly from the tapered extensions, the body is of generally cylindrical shape with longitudinal ribs 24 projecting radially and outwardly adjacent the central plane on diametrically opposite sides of the body and an intermediate radially projecting longitudinal rib 25 on one part of the body between the intermediate ribs. The intermediate ribs fits into a slot (not shown) in the tone arm so as to locate the cartridge in the proper angular position with respect to the arm.

Movements of the styli 17 are converted into electrical signals through the medium of an electro-mechanical transducer element 26 which forms part of the transducer and stylus supporting member 20. The element is elongated and of rectangular cross section and is mounted within the hollow interior of the body by spaced blocks 27 and 28 of resilient plastic material. A larger one 27 of these blocks receives a central portion of the element snugly in an axial hole 29 (FIG. 5) and is cylindrical so as to fit snugly within a cylindrical cavity 30 defined by the body halves. A second block 28 snugly receiving the end portion of the element remote from the housing opening 21 and the styli is also of cylindrical shape and is formed with radially projecting ribs 31. These ribs fit into recesses 32 in the body halves (FIG. 6) and are clamped between the halves to center the block in a cavity 33 in the body slightly larger than the block. The extreme end of the transducer element abuts a disk 34 of resilient material fitting snugly in another cavity in the body. I

The styli 17 are fastened in and project from opposite sides of a block 35 of rigid material secured to the free end of the transducer element 26 beyond the central resilie'nt block 28. Each stylus is disposed at an angle with respect to the longitudinal axis of the element so as to be inclined away from a perpendicular to the record in the direction of travel of the stylus relative to the record as shown in FIG. 1 when the cartridge 15 is turned in the tone arm 16 to dispose the stylus in an active position depending below the cartridge.

In the use of cartridges of the above character, the entire cartridge 16 rather than just the styli 17 are replaced when the styli become worn. To effect such removal, the end portion of the cartridge projecting beyond the tone arm 16 is grasped by the users fingers and the. cartridge is pulled along its axis and out of the arm. Sometimes it is found, after removal of the cartridge, that the styli are not worn enough for replacement but can be used for a longer time by replacing the cartridge in the arm. For this reason, it is desirable that the styli and the transducer element 26 remain assembled within the housing 19 during removal of the cartridge from the tone arm.

The present invention, in one of its aspects, contemplates a novel construct-ion of the transducer and stylus supporting member 20 and the housing 19 for facilitating removal of the cartridge from the tone arm 16 while insuring that the parts remain assembled during such removal. To this end, shoulders or abutments 36 and 37 are formed on the housing extensions 22 and the rigid stylus supporting block 35 in opposing relation so as tc engage each other and prevent movement of the block and thus the transducer element 26 outwardly with respect to and beyond the extensions. These shoulders extend transversely of and face along the longitudinal axis of the element and toward each other and are brought into opposing relation in a direction along the assess? axis automatically as an incident to assembly of the parts of the cartridge.

To prevent outward movement of the stylus block 35 even if the block is displaced transversely of the cartridge axis from its normal position between the housing extensions 22, it is preferred to form one shoulder 36 on each extension and an opposing shoulder 37 on the adjacent side of the block. Thus, there are two sets of opposing shoulders, one set on each side of the block. The housing shoulders 36 in the present instance are simply the inwardly facing sides of cylindrical lugs 38 projecting inwardly from the end portions of the extensions. The shoulders 37 on the stylus block are flat outwardly facing surfaces on an enlarged inner end portion of the block.

By virtue of the interengaging shoulders 36 and 37 on the stylus block 35 and the housing extensions 22, the block remains within the housing even though it may be grasped and pulled outwardly inadvertently in an attempt to grasp only the extensions. This makes it possible to provide, on the outer sides of the extensions 22, gripping means 39 extending circumferentially around the extensions a substantial distance thereby facilitating the grasping and removal of the cartridge. Such means is in the form of arcuate ribs spaced along the outer side of each extension and projecting radially and outwardly therefrom. Herein, the ribs are of generally V-shaped cross section having their front or outer sides merging with the extensions and their inner sides approximately normal to the extensions (FIGS. 3 and 4) to provide an inwardly facing surface for gripping. Each rib extends completely around the outer side of its extension between the flat surfaces 23 defining the sides of the extension.

The electrical signals resulting from bending of the transducer element 26 are transmitted to the exterior of the cartridge through contact strips 40 engaging opposite sides of the element and contact plates 41 having portions disposed exteriorly of the cartridge and engageable with contact members (not shown) on the tone arm 16. The contact strips '40 in this instance are of U-shape and are supported by the ribbed resilient mounting block 28. Each strip has two laterally spaced legs an inner one of which lies along the element between the element and the ribbed block and the outer one of which lies along the outer side of the block between the ribs 31. The :ontact plates 41 engage the outer legs of the strips inside of the housing and project through'slots 42 in the housing walls to the exterior.

In accordance with another aspect of the present invention, the contact plates 41 and adjacent parts of the rousing 19 coact in a novel manner to simplify the con struction and assembly of the plates in the housing while .nsuring that they remain in assembled relation during subsequent handling. To this end, projecting and re- :essed elements 43 and 44 are formed on the plates and die housing to interfit with each other as an incident to assembly and to remain in engagement to prevent movenent of the plates relative to the housing. The formation of the plates facilitated by forming the projections 43 as lugs projecting inwardly from the housing halves and .nto the recesses 44 which are stamped out of the edge portions of the plates. The lugs project transversely of :he housing axis and partially across the slots 42 but short sf the remote edges of the slots (FIGS. 9 and 11) so as permit the recessed edges of the plates to move past :he lugs during edgewise movement of the plates into the slots, the recessed edges then being shifted transversely of the housing axis so that the defining edges of the recesses are disposed on opposite sides of the lugs.

The contact plates 41 in this instance are of rectangular ihape and the housing slots 42 are of rectangular cross section and of slightly greater width than the plates. The lugs 43 are cylindrical and project across the slots and toward the housing axis a distance less than the thickness of the slots (FIGS. 10 and 11). In order to move past dthe inner ends of the lugs, the recessed edge portions of the plates are bent laterally at an angle to the remainder of the plates. These bent portions are shifted away from each other and into interlocking relation with the lugs by the resilient disk 34 when the halves of the housing are assembled, the disk then being compressed between the plates and urging them outwardly (see FIGS. 11 and 12).

Assuming that the transducer element 26, stylus block 35, styli 17, resilient blocks 27 and 28 and contact strips 40 have been put together to form a subassembly as shown in FIG. 5 and that one contact plate 41 has been inserted into the slot 42 of one-half of the housing, the assembly of the cartridge parts is completed by first inserting the subassembly into that housing half as shown in FIGS. 6 and 7, one contact strip 40 thereby being brought into engagement with the contact plate. During the previous insertion of the plate edgewise into the housing slot 42, the recessed edge of the plate moved past the lug 43 due to the lateral bend in the plate. When the plate and subassembly are in their proper positions as shown in FIG. 6, the resilient disk 34 is inserted on top of the plate. Next, the other plate is inserted in the slot of the other half of the housing and that half is laid on the first half with a suitable adhesive on the abutting edges of the halves as an incident to this movement, the resilient disk is compressed between the contact plates to urge their recessed edge portions into over-locking relation with the lugs as shown in FIGS. 11 and 12. Also, both shoulders 36 on the housing extensions 22 thereby are brought into opposite relation with respect to shoulders 37 on the rigid stylus block. The assembly is then complete with the adhesive holding the housing halves together.

It will be apparent that the shoulders 36 and 37 and the lugs 43 and contact plates 41 are brought into operative relation automatically as an incident to assembly of the parts. Once the assembly is complete, the lugs prevent edgewise movement out of the housing slots 42. The shoulders 36 and 37 likewise abut each other to prevent endwise withdrawal of the transducer element 26 and stylus block 35 out of the housing not only during service use of the cartridge but also in case the block is grasped inadvertently during removal of the cartridge. By virtue of the shoulders, the exterior ribs 39 may extend around the circumference of the extensions 22 thereby facilitating the grasping of the cartridge.

I claim as my invention:

1. In a cartridge for a phonograph pickup, the combination of an elongated hollow housing having an opening at one end defined by two extensions tapering outwardly along the housing and spaced apart transversely of the longitudinal axis of the housing, an elongated transducer and stylus supporting member supported Within said housing and along said axis thereof with one end portion disposed between said housing extensions and supporting at least one stylus for engagement with a phonograph record externally of the housing, said end portion of said member having at least one shoulder spaced from the adjacent stylus supporting end of the member and facing along said axis toward such end and the exterior of the housing, and means on the inner side of at least one of said extensions defining a shoulder facing inwardly toward said shoulder on said member and projecting from the extension toward said axis far enough to engage the shoulder on the member and block movement of the member along said axis and out of said housing, and at least one rib projecting radially and outwardly from and extending circumferentially around each of said extensions to facilitate grasping of said housing adjacent said one end for removal of the housing from a supporting structure.

2. In a cartridge for a phonograph pickup, the combination of an elongated hollow housing having an opening at one end defined by two extensions tapering outwardly along the housing and spaced apart transversely of the longitudinal axis of the housing, an elongated transducer and stylus supporting member supported within said housing and along said axis thereof with one end portion disposed between said housing extensions and supporting at least one stylus for engagement with a phonograph record externally of the housing, said end portion of said member having shoulders spaced from the adjacent stylus supporting end of the member on opposite sides of the member and facing along said axis toward such end and the exterior of the housing, and means on the inner sides of said extensions defining shoulders facing inwardly toward said shoulders on said member and projecting from the extension toward said axis far enough to engage the shoulders on the member and block movement of the member along said axis and out of said housing.

3. In a cartridge for a phonograph pickup, the combination of an elongated hollow housing having an opening at one end defined by two extensions spaced apart transversely of the longitudinal axis of the housing and each tapering outwardly, an elongated transducer and stylus supporting member supported within said housing and along said axis thereof with one end portion disposed between said housing extensions and supporting at least one stylus for engagement with a phonograph record externally of the housing, said end portion of said member having at least one shoulder spaced from the adjacent stylus supporting end of the member and facing along said axis toward such end and the exterior of the housing, and means on the inner side of at least one of said extensions defining a shoulder facing inwardly toward said shoulder on said member and projecting from the extension toward said axis far enough to engage the shoulder on the member and block movement of the member along said axis and out of said housing.

4. In a cartridge for a phonograph pickup, the combination of an elongated hollow housing divided into two parts along a plane through the longitudinal axis of the housing and having an elongated hollow cavity opening at one end to the exterior of the housing, an elongated transducer and stylus supporting member extending along said axis within said cavity and having one end portion projecting through said opening and carrying a stylus for engagement with a phonograph record externally of the housing, each of said housing parts having an elongated slot paralleling said plane and extending transversely of said axis and through opposite sides of said housing to the exterior thereof from said cavity adjacent the other end of said member and the other end of said housing remote from said cavity opening, contact plates of generally rectangular shape disposed within said slots and each having one fiat end portion paralleling said plane and its other flat end portion adjacent said other housing end inclined toward said axis and having a central recess along one edge, lugs projecting from said housing transversely of said axis and into said plate recesses to locate the plates relative to said housing and prevent the same from shifting edgewise out of said housing slots, and contact strips engaging opposite sides of said member and said plates individually within said housing.

5. In a cartridge for a phonograph pickup, the combination of an elongated hollow housing divided into two parts along a plane through the longitudinal axis of the housing and having an elongated hollow cavity opening at one end to the exterior of the housing, an elongated transducer and stylus supporting member extending along said axis within said cavity and having one end portion projecting through said opening and carrying a stylus for engagement with a phonograph record externally of the housing, each of said housing parts having an elongated slot paralleling said plane and extending transversely of said axis and through opposite sides of said housing to the exterior thereof from said cavity adjacent the other end of said member and the other end of said housing remote from said cavity opening, contact plates of generally rectangular shape disposed within said slots and having a recess, lugs projecting from said housing transversely of said axis and into said plate recesses to locate the plates relative to said housing and prevent the same from shifting out edgewise of said housing slots, and contact strips engaging opposite sides of said member and said plates individually.

6. In a cartridge for a phonograph pickup, the combination of an elongated hollow housing divide-d into two parts along a plane through the longitudinal axis of the housing and having an elongated hollow cavity opening at one end to the exterior of the housing, an elongated transducer and stylus supporting member extending along said axis within said cavity and having one end portion projecting through said opening and carrying a stylus for engagement with a phonograph record externally of the housing, each of said housing parts having an elongated slot paralleling said plane and extending transversely of said axis and through opposite sides of said housing to the exterior thereof from said cavity adjacent the other end of said member and the other end of said housing remote from said cavity opening, contact plates of generally rectangular shape disposed within said slots, projecting and recessed parts on said plates and said housing inter-engaging each other to locate the plates relative to the housing and prevent the same from shifting out of said housing slots, and contact strips engaging opposite sides of said member and said plates individually.

References Cited in the file of this patent UNITED STATES PATENTS Dally Ian. 21, 1958 

